Locomotives traditionally include a traction motor that drives one or more wheel sets and propels the locomotive. The traction motor may receive power in the form of electricity from a generator powered by one or more main engines of the locomotive. The traction motor that drives the wheel sets may include a motor shaft connected to the wheel sets. The motor shaft may be connected to a pinion gear inside a two-piece matable gear case, and the main shaft may extend through an opening in a wall of the gear case. The pinion gear may drive a bull gear also contained within the gear case. The bull gear may be connected to a wheel shaft that may extend through an additional opening in the gear case wall. The gear case may be mounted to the motor via a flange, and the gear case may include seals located around the motor shaft and wheel shaft. The seals may be configured to substantially eliminate leakage of a lubricant through the openings in the walls of the gear case during use.
During operation, the locomotive may experience vibratory loading while traversing an uneven support surface. For example, in cold weather, the ground may freeze unevenly causing the tracks on which the locomotive rides to shift. Such shifting may cause non-uniform rotation of wheels and may cause components connected to the wheels to vibrate. For example, the wheels may transfer such vibration to the bull gear and pinion gear via the wheel shaft. The vibration may then pass from the gears, through the motor shaft, and into the traction motor. As the vibration causes the rigidly mounted components to move, distances between the rigidly mounted components may increase or decrease. In some embodiments, the seals located between the components may expand and contract. However, since such seals are typically made of a flexible material, the seals are usually not configured to limit the range of motion of such rigidly mounted components relative to each other. Instead, the relative movement between the various rigidly mounted components may cause tensile or compressive stresses to build over time, and eventually, such stresses may cause system failure.
One method of sealing a locomotive gear case is described in U.S. Pat. No. 4,347,759 (“the '759 patent”) to Renk. The '759 patent describes a lubricant-retaining device for use with a gear case having a pair of matable sections with a shaft-receiving opening therein. The lubricant-retaining device extends inwardly to the interior of the gear case to reduce lubricant flow through the opening.
While the system disclosed in the '759 patent may assist in retaining a lubricant within the gear case in some applications, the system is not designed to limit the freedom of motion of its components during vibratory loading. As a result, the components of the system may suffer premature failure due to stresses caused by vibration.
The exemplary embodiments of the present disclosure are directed at solving one or more of the problems set forth above and/or other problems in the art.